Machine for simultaneously conveying and washing dishware



Dec. 6, 1966 E. NASLUND 3,289,682

MACHINE FOR SIMULTANEOUSLY CONVEYING AND WASHING DISHWARE Filed Nov. 27, 1964 2 Sheets-Sheet 2 12 M /\46 mm 1e 48 86 as 38 INVENTQR q ERIK NASLUND BY MM ATTQRNEY United States Patent 3,289,682 MACHINE FOR SIMULTANEOUSLY CONVEYING AND WASHING DISHWARE Erik Naslund, Santa Clara, Calif., assignor to FMC Corporation, a corporation of Delaware Filed Nov. 27, 1964, Ser. No. 414,233 3 Claims. (Cl. 134-125) The present invention pertains to scullery equipment and more particularly concerns a machine for simultaneously conveying and washing dishware.

Presently available commercial dishwashers of the res taurant and institution type are often characterized in that the detergent solution is applied in the form of a low velocity spray while the dishes are conveyed at slow speed. In order to allow suflicient time for the detergent solution to penetrate the soil, the detergent solution is allowed to remain thereon for perhaps fifteen seconds or so, after which the dishes are rinsed with hot water. The water is collected and added to the detergent solution supply tank. Since this dilutes and increases the volume of the detergent solution, part of the solution must be periodically drained from the supply tank, and concentrated detergent solution must be periodically added to maintain the desired concentration of detergent for the initial spray.

The present invention contemplates that the dishes at some early stage in a dishwashing system, such as when they are sorted, be conveyed through a fog or mist of detergent solution, and at a subsequent downstream point sufliciently spaced from the detergent mist so that the detergent can penetrate the soil on the dishes, that the dishes be washed by high velocity sprays of hot water. The detergent mist and the wash water are isolated from one another and are supplied at flow rates which are substantially less than in the existing systems above described. Accordingly, the present dishwashing system is less costly to operate but is at least as rapid in operation as systems which are presently in use.

The present invention particularly concerns the dish conveying apparatus and the high velocity wash water application to the dishes in accordance with the foregoing outline.

An object of the present invention is to provide irriproved apparatus for simultaneously conveying dishware at relatively high speed and impinging high velocity spray against all surfaces of the dishware to remove the soil.

Another object of the invention is to provide dishware conveying apparatus wherein successive areas of the dishes are exposed to overhead and underhead sprays directed at the peripheral areas of the plates.

A further object is to provide a high speed conveyor for dishware wherein the dishes are supported and conveyed by means other than a coextensive underlying conveyor flight whereby soil which is washed from the plates is less likely to be maintained either adjacent to or in contact with the dishes.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings, wherein:

FIGURE 1 is a schematic longitudinal section through the dishware conveying apparatus of the present invention.

FIGURE 2 is an enlarged portion of the apparatus shown in FIGURE 1.

FIGURE 3 is a schematic horizontal section, indicated by the lines 3-3 on FIGURE 1, and depicts the entire width of the conveying apparatus.

FIGURE 4 is a vertical, transverse, schematic section taken along lines 4-4 on FIGURE 3.

The conveying and washing apparatus (FIGS. 1 and 3) includes laterally spaced endless chains 12 and 14 which are trained around a pair of idler sprockets 16 and a pair of drive sprockets 18 (only one being shown).

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The pairs of sprockets 16 and 18 are respectively mounted within a cabinet or frame 19 on an idler shaft 20 and a drive-shaft 22, the bearings 24 (FIG. 4) for which are supported on the inner surfaces of side walls 26 and 28 of the cabinet. Driveshaft 22 projects through the wall 26 and is continuously driven by conventional drive means, not shown, when the conveying apparatus 10 is operating.

The drive direction is such that the upper flights of the chains 12 and 14 move from an inlet end wall 30 toward an outlet end wall 32, each of said end walls being provided with a corresponding aperture aligned with the upper, conveying flight 34 of the chains 12 and 14. Top and bottom walls 36 and 38, and flexible entrance and exit closure flaps 40 and 42 complete the cabinet 19 and form a splash-proof enclosure which can drain through an aperture 44 (FIG. 4) between the bottom edge of the side wall 28 and the bottom wall 38.

A series of spaced propelling lugs 46 are centrally mounted upon pairs of transverse rods 48 that are connected at each end to the chains 12 and 14. Each lug 46 (FIGS. 2 and 3) has a leading surface 50 that is arranged to engage the trailing portion of the rim 52 of an inverted plate 54 when the plate is being propelled by the lugs 46 on the upper flights of the chains 12 and 14. During such propelling movement, the plates 54 are supported by inwardly projecting support rails 56 and 53 (FIGS. 3 and 4) that are respectively mounted on the side walls 26 and 28, and the plates lie under similar guide rails 55 and 57. The lower rails 56 and 58 have vertical flanges 56a and 58a that are laterally spaced by a distance slightly greater than the diameter of the dishes 54 and which center and guide the dishes as they are moved along the rails.

In order to assure substantially frictionless travel of the plates 54 along the support rails 56 and. 58, the rails may be provided with a coextensive facing (not shown), of Nylon or a fluoroethylene polymer, to support the plate rims. Near the inlet end wall 36 and the outlet end wall 32, the support rails 56 and 58 may merge with other plate support rails, such as the rails 60 shown in FIGURE 1, which area part of associated apparatus not a part of the present invention. The incoming plates are fed in timed relation to the conveying chains 12 and 14, by means not shown and not a part of the present invention, so that each plate is delivered into the cabinet 19 between the upper and lower pairs of rails 55, 57 and 56, 58 ahead of a pusher lug 46 as the lug approaches the upper flight from the idler sprockets 16.

Projecting inwardly through the side wall 26 (FIGS. 3 and 4) above the upper rails 55 and 57 are conduits 62, 64 and 66 which are supplied with hot water at about psi. from a common supply line 70. Conduits 62, 64 and 66 are each provided with downwardly directed spray nozzles 72 so located that the nozzles are equally spaced across the conveying path of the plates. The spray pattern from each nozzle 72 is fan-shaped viewed along the length of the conveying path, and so narrow in its other dimension as to provide a virtual knife-edge of high velocity spray. Vertically aligned with the nozzles 72 on the conduits 62 and 66 are notches 74 in the guide rails 55 and 57. The notches 74 extend laterally inward from their edges 55b and 57b to the vertical guide flanges 56a and 58a, respectively. These notches expose successive areas of the moving plates to the sprays from the nozzles 72 on conduits 62 and 66. Conduit 64 is provided with a spray nozzle 72 that is centered over the conveyor to impinge upon the unmasked parts of the plates.

The liquid pattern from each spray nozzle overlaps the area of the plate which is covered by the adjacent spray.

Vertically aligned, though not necessarily so, with the upper conduits 62, 64 and 66, are lower conduits 82, 84 and 86 (FIGS. 2 and 4). The lower conduits extend transversely under the upper conveying flights of the chains 12 and 14, and are spaced below the plates by about the same distance that the uppermost conduits 62, 64 and 66 are spaced above the plates. Each of the lower conduits is provided with one or more nozzles 72 which are aligned with the upper nozzles, and are supplied with water at high-pressure from the same source which supplies the upper nozzles.

The lower plate-support rails 56 and 58 are provided with notches '75 (FIG. 3) that extend laterally inward from the edges 56b and 58b to the vertical guide fianges 56a and 5612, respectively. These notches expose the undersurfaces of the plates supported by the lower rails 56, 58 successively to the high pressure, knife-edged water sprays from the nozzles 72 on the lower conduits 82 and 86. At the same time, the central portions of the plates are impinged by spray emanating from the nozzle on the lower central conduit 84.

In operation, the driveshaft 22 (FIG. 1) is continuously rotated to advance the uppermost pusher lugs 46 toward the outlet end wall 32, and inverted plates 54 are fed into the cabinet 19 in timed relation to the pusher lugs so that each plate leads a lug. The plates have been previously subjected to a fog or mist spray of detergent solution at an upstream point (not shown) to penetrate the soil on the plates and thereby aid the knife-edge, high pressure spray from the nozzles 72 in cleansing the plates. The spray liquid is preferably clear, hot water, supplied at about 100 psi. At or about this pressure, a conveying speed in the vicinity of perhaps three inches per secnd and a spray pattern approximately inch wide, any given point on a plate is washed for only ,5 of a second. However, this washing duration has been found to be ample time to thoroughly cleanse the plates and the minimal amounts of wash water thus required can be discarded rather than collected, filtered and reconstituted with detergent solution as is presently done in commercial dishwashing systems.

It will be understood that the conveying and washing apparatus is capable, with certain dimensional changes, of handling all types of dishware, and that the apparatus is not limited to use with inverted dishware.

Having thus described the invention, that which is believed to be new, and for which protection by Letters Patent is desired, is:

1. Apparatus for washing dishes comprising longitudinally extending laterally spaced parallel upper and lower side rails for receiving the opposed rim portions of dishes, power driven dish pusher means individually engaged with the trailing rim portions of the dishes for propelling the dishes along said rails, each of said rails having interrupted portions forming laterally extending vertical apertures so that successive areas of the dishes conveyed along said rails are exposed through said apertures, upper and lower side spray nozzles spaced from and in alignment with said apertures for directing liquid spray onto those portions of the dishes which traverse said apertures, and central spray nozzles for directing liquid spray onto those portions of the dishes which lie between said side rails.

2. Apparatus for washing dishes comprising longitudinally extending laterally spaced upper and lower side rails for receiving the opposed rim portions of dishes, each of said rails having interrupted portions forming laterally extending elongate vertical apertures so that successive areas of the dishes conveyed along said rails are exposed through said apertures, upper and lower side spray nozzles spaced from and in alignment with said apertures for directing liquid spray onto those portions of the dishes which traverse said apertures, central spray nozzles for directing liquid spray onto those portions of the dishes which lie between said side rails, a pair of laterally spaced, endless band members passing around wheels and having upper and lower reaches, longitudinally spaced transverse rod members connecting said bands, and lugs on the center of each rod member for engaging the trailing rim portions of the dishes, the lower set of said spray nozzles being mounted between the upper and lower reaches of said endless band members.

3. Apparatus for washing dishware comprising a frame, two parallel support rails mounted on said frame to slidably support opposed rim portions of individual dishes and each having an upstanding portion for laterally restraining the dishes, a guide rail secured to said frame in overlying relation to each of said support rails and the dishes thereon, an endless chain mounted adjacent each of said support rails, transverse rods interconnecting said chains, pusher lugs secured to said rods and projecting upward when carried by the upper flights of said chains into propelling engagement with the dishes supported on said support rails, two superposed conduits mounted on said frame and extending transversely of said upper chain flights in vertically straddling relation thereto, spray nozzles mounted on each conduit in substantial vertical alignment with the transverse outer portions of dishes carried between said support and guide rails, and means defining apertures in said support and guide rails in alignment with the adjacent spray nozzles whereby spray emanating from the nozzles tranverses and impinges upon the dishes propelled along said support rails by said pusher lugs.

References Cited by the Examiner UNITED STATES PATENTS 1,487,062 3/1924 Hohl 134-423 X 2,250,238 7/1941 Smith 134-72 2,271,436 1/ 1942 Lathrop 198229 2,962,741 12/ 1960 Petrillo 1577 X 3,213,472 10/1965 Cocchiaraley et al. 134--72 X FOREIGN PATENTS 240,942 10/ 1925 Great Britain.

CHARLES A. WILLMUTH, Primary Examiner.

BLEUTGE, Assistant Examiner, 

1. APPARATUS FOR WASHING DISHES COMPRISING LONGITUDINALLY EXTENDING LATERALLY SPACED PARALLEL UPPER AND LOWER SIDE RAILS FOR RECEIVING THE OPPOSED RIM PORTIONS OF DISHES, POWER DRIVEN DISH PUSHER MEANS INDIVIDUALLY ENGAGED WITH THE TRAILING RIM PORTIONS OF THE DISHES FOR PROPELLING THE DISHES ALONG SAID RAILS, EACH OF SAID RAILS HAVING INTERRUPTED PORTIONS FORMING LATERALLY EXTENDING VERTICAL APERTURES SO THAT SUCCESSIVE AREAS OF THE DISHES CONVEYED ALONG SAID RAILS ARE EXPOSED THROUGH SAID APERTURES, UPPER AND LOWER SIDE SPRAY NOZZLES SPACED FROM AND IN ALIGNMENT WITH SAID APERTURES FOR DIRECTING LIQUID SPRAY ONTO THOSE PORTIONS OF THE DISHES WHICH TRAVERSE SAID APERTURES, AND CENTRAL SPRAY NOZZLES FOR DIRECTING LIQUID SPRAY ONTO THOSE PORTIONS OF THE DISHES WHICH LIE BETWEEN SAID SIDE RAILS. 